Air-to-air cooling assembly

ABSTRACT

An air-to-air cooling assembly is disclosed. The air-to-air cooling assembly includes an inlet tank having an inlet configured to receive an air flow, and a wall forming a space within the inlet tank. The air-to-air cooling assembly also includes a perforated plate disposed adjacent the inlet of the tank and arranged substantially perpendicular to the air flow. The air-to-air cooling assembly further includes a plurality of pressure balancing openings at predetermined locations on the wall and configured to direct air into and out of the space.

TECHNICAL FIELD

The present disclosure relates generally to a cooling assembly and, more particularly, to an air-to-air cooling assembly.

BACKGROUND

Air-to-air cooling assemblies are heat exchangers that employ one relatively cooler flow of air as a heat transfer/exchange medium to reduce the temperature of another relatively hotter flow of air. Air-to-air cooling assemblies can find applications in industrial applications, such as modern engine systems. For example, one or more compressors are often employed in modern engine systems to compress engine intake air in turbocharged or supercharged applications. Compression of the intake air by the compressors may increase the temperature of the intake air substantially above ambient temperature. An air-to-air cooling assembly may be employed to reduce the temperature of the compressed intake air before the compressed air is supplied to the engine for combustion.

A typical air-to-air cooling assembly may include an inlet tank, an outlet tank, and a plurality of core tubes connecting the inlet tank and the outlet tank. When hot air is directed from the inlet tank through the core tubes, heat exchange may occur between the hot air and cool air flowing outside the core tubes. The temperature of the hot air inside the air-to-air cooling assembly may be reduced due to the heat exchange with the cool air flow. Depending on applications, an air-to-air cooling assembly may be referred to in various ways, such as an aftercooler or an intercooler. For example, an aftercooling assembly may be disposed downstream of a compressor and upstream of an air intake port, e.g., an air intake manifold, of the engine. An intercooling assembly typically may be disposed between two compressors in order to cool the compressed, hot air from the first compressor before the air is further compressed by the second compressor. When the compressed, hot air is cooled, the air may become dense, enabling a larger amount of compressed air to be taken into the engine for combustion, thereby boosting engine power.

When the compressed air flows into the inlet tank at a high velocity and contacts the bottom and the side walls of the inlet tank, turbulence and recirculation may be created, which may cause uneven pressure distribution in the air flow. As a result, some portions of the air flow may have relatively higher air pressures than other portions of the air flow. Consequently, the mass distribution of the air flow in the inlet tank may become non-uniform, and this may lead to a non-uniform air flow distribution in the core tubes. Those core tubes receiving more air, and thus more air mass, may carry more thermal energy than other core tubes, since thermal energy is directly related to the mass of the air the core tubes carry. Those core tubes carrying more thermal energy may have a higher temperature than those core tubes carrying less thermal energy. Therefore, a thermal gradient may exist among the core tubes due to the uneven thermal energy distribution. The thermal gradient may induce thermal stresses in the core tubes, causing some core tubes to expand more than the others. As a result, joints between the core tubes and the inlet tank and/or the outlet tank may break due to uneven expansion in the inlet and outlet tanks and core tubes, causing damage to the cooling assembly and leakage of the air flow. Accordingly, a uniform air distribution in the inlet tank may be desired in order to prevent or reduce thermal gradient and the resulting damage to the cooling assembly.

A heat exchanger with mechanisms for steam distribution is described in U.S. Pat. No. 6,729,386 (the '386 patent) issued to Sather on May 4, 2004. The heat exchanger includes a steam inlet header having an outer conduit and an inner conduit. A series of openings are provided on the inner conduit adjacent the top of the inner conduit. The openings allow steam to flow from the inner conduit to the outer conduit. Steam in the outer conduit is further distributed to a plurality of tubes connected with the outer conduit.

Although the heat exchanger of the '386 patent may improve distribution of steam among the tubes, it may be problematic. For example, without any structure to reduce the velocity of the steam, the steam may impact the end wall at its full velocity and may create turbulence and recirculation. The resulting turbulence and recirculation pockets may cause uneven pressure in the steam flow, and consequently, non-uniform distribution of the steam flow in the inner conduit. In addition, because the openings appear to only allow steam to flow from the inner conduit to the outer conduit, the steam cannot flow back to the inner conduit from the outer conduit. Therefore, the pressure of the steam flow at different locations of the inner and outer conduits may not be balanced. The imbalanced pressure distribution in the inner and outer conduits may result in non-uniform stream distribution in the inner and outer conduits, and subsequently, in the tubes.

The system and method of the present disclosure are directed toward improvements in the existing technology.

SUMMARY

In one aspect, the present disclosure is directed to an air-to-air cooling assembly. The air-to-air cooling assembly includes an inlet tank having an inlet configured to receive an air flow, and a wall forming a space within the inlet tank. The air-to-air cooling assembly also includes a perforated plate disposed adjacent the inlet of the tank and arranged substantially perpendicular to the air flow. The air-to-air cooling assembly further includes a plurality of pressure balancing openings at predetermined locations on the wall and configured to direct air into and out of the space.

In another aspect, the present disclosure is directed to a method of distributing air in an air-to-air cooling assembly. The method includes directing an air flow into an inlet tank through an inlet. The method also includes directing the air flow through a perforated plate disposed adjacent the inlet and substantially perpendicular to the air flow. The method further includes directing the air flow into and out of a space formed by a wall of the inlet tank through a plurality of pressure balancing openings on the wall.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of an exemplary engine system in which the disclosed air-to-air cooling assembly may be employed;

FIG. 2 is a schematic illustration of an exemplary disclosed air-to-air cooling assembly;

FIG. 3 is a schematic cross-section view of an embodiment of an inlet tank of an exemplary disclosed air-to-air cooling assembly;

FIG. 4 is a schematic cross-section view along line 4-4 of the inlet tank shown in FIG. 3;

FIG. 5A is a diagrammatic illustration of an exemplary perforated plate which can be used in the inlet tank shown in FIG. 3;

FIG. 5B is a diagrammatic illustration of an exemplary perforated plate which can be used in the inlet tank shown in FIG. 3;

FIG. 5C is a diagrammatic illustration of an exemplary perforated plate which can be used in the inlet tank shown in FIG. 3;

FIG. 5D is a diagrammatic illustration of an exemplary perforated plate which can be used in the inlet tank shown in FIG. 3;

FIG. 6 is a schematic cross-section view of an embodiment of an inlet tank of an exemplary disclosed air-to-air cooling assembly;

FIG. 7 is a schematic cross-section view along line 7-7 of an embodiment of an inlet tank shown in FIG. 6;

FIG. 8A is a schematic cross-section view of an embodiment of an inlet tank of an exemplary disclosed air-to-air cooling assembly;

FIG. 8B is partial cross-section view of an embodiment of an inlet tank; and

FIG. 9 is a diagrammatic illustration of an exemplary perforated plate with honey-comb structure.

DETAILED DESCRIPTION

FIG. 1 is a schematic illustration of an exemplary engine system 100 in which the disclosed air-to-air cooling assembly may be employed. The engine system 100 may include an engine 10 including a plurality of combustion chambers 20 configured to combust a mixture of air and fuel to produce power and produce exhaust gases as a byproduct. An air intake system 50 may be associated with the engine 10 and configured to direct intake air to the combustion chambers 20 for combustion. The air intake system 50 may include an air intake manifold 15 associated with the engine 10 and configured to distribute air to the engine 10 for combustion. An exhaust system 60 may be associated with the engine 10. The exhaust system 60 may include an exhaust manifold 25 associated with the engine 10 and configured to collect exhaust gases from the combustion chambers 20 of the engine 10. Exhaust system 60 may include one or more exhaust gas treatment devices 65, such as a catalyst, a particulate filter, a NO_(x) removing device, an SO_(x) removing device, etc.

The engine system 100 may also include one or more turbochargers or superchargers for compressing engine intake air. In the exemplary embodiment shown in FIG. 1, the engine system 100 includes two turbochargers. A first turbocharger 30 may include a high pressure turbine 32 and a high pressure compressor 36 drivingly connected through a first common rotating shaft 34. When the high pressure turbine 32 rotates, the first common rotating shaft 34 may also rotate, causing the high pressure compressor 36 to rotate. Similarly, a second turbocharger 40 may include a low pressure turbine 42 and a low pressure compressor 46 drivingly connected through a second common rotating shaft 44. The high pressure turbine 32 may be located downstream of the exhaust manifold 25 to receive exhaust gases at relatively high pressure from the exhaust manifold 25. The low pressure turbine 42 may be located downstream of the high pressure turbine 32 to receive exhaust gases at relatively low pressure from the high pressure turbine 32. The high pressure compressor 36 may be located downstream of the low pressure compressor 46. The low pressure compressor 46 may draw air from the atmosphere, and may compress the air. After being compressed by the low pressure compressor 46, the temperature and the pressure of the air may be significantly elevated with respect to the ambient air temperature and pressure in the atmosphere. The compressed air then may be directed to the high pressure compressor 36 for further compression.

The air intake system 50 may also include a first air-to-air cooling assembly 55 and a second air-to-air cooling assembly 55′ configured to cool the compressed air from the low pressure compressor 46 and the high pressure compressor 36. The first air-to-air cooling assembly 55 may be located between the low pressure compressor 46 and the high pressure compressor 36 and may be configured to cool the compressed air from the low pressure compressor 46. The first air-to-air cooling assembly 55 may be referred to as an intercooler. After flowing through the first air-to-air cooling assembly 55, the air may be directed to the high pressure compressor 36, where the air is further compressed. The second air-to-air cooling assembly 55′ may be located downstream of the high pressure compressor 36 and upstream of the air intake manifold 15. The second air-to-air cooling assembly 55′ may cool the compressed air from the high pressure compressor 36 before the compressed air is directed to the air intake manifold 15 and the engine 10 for combustion. The second air-to-air cooling assembly 55′ may be referred to as an aftercooler.

FIG. 2 schematically illustrates an exemplary air-to-air cooling assembly, which may be employed as the first air-to-air cooling assembly 55 or the second air-to-air cooling assembly 55′. For illustrative purposes and for the sake of convenience, the schematically illustrated air-to-air cooling assembly is referred to as the first air-to-air cooling assembly 55. As shown in FIG. 2, the first air-to-air cooling assembly 55 may include an inlet tank 200, an outlet tank 230, and a plurality of core tubes 220 connecting the inlet tank 200 and the outlet tank 230. The inlet tank 200 may include an air inlet 210 configured to receive an air flow. The outlet tank 230 may include an air outlet 240. An air flow 201, which may be directed from the high pressure compressor 36 or the low pressure compressor 46, is directed into the inlet tank 200, the core tubes 220, and the outlet tank 230. The flow direction of the air flow 201 is diagrammatically illustrated by the arrows shown in FIG. 2. The inlet tank 200 and the outlet tank 230 may both include two ends (left and right ends as shown in FIG. 2) and a longitudinally extended body between the two ends. Other suitable shapes also are contemplated for the inlet tank 200 and the outlet tank 230. Details of the inlet tank 200 will be discussed below with reference to FIGS. 3-5.

FIG. 3 is a schematic illustration of an exemplary cross-section of one embodiment of the inlet tank 200, which may be employed in the first air-to-air cooling assembly 55 shown in FIG. 2. As shown in FIG. 3, the inlet tank 200 may include a top portion 203, a bottom portion 205, and a double wall at the left and right ends. The inlet tank 200 also may include front and back sides illustrated in FIG. 4. The double wall may include an inner wall 204 and an outer wall 202 surrounding the inner wall 204. The inner wall 204 may enclose an inner space 255. The outer wall 202 and the inner wall 204 may form an outer space 206 therebetween. The core tubes 220 may be connected to the bottom portion 205 and may receive air from the inner space 255 of the inlet tank 200.

As shown in FIG. 3, the inlet tank 200 may also include a perforated plate 250 disposed adjacent the air inlet 210 and arranged substantially perpendicular to the air flow 201 flowing into the inlet tank 200. As illustrated in FIG. 3, in one embodiment, the perforated plate 250 may be perpendicularly fixed to a portion of the inner wall 204 adjacent the inlet 210 of the inlet tank 200. The height of the perforated plate 250 from the bottom portion 205 may be any suitable height. The length of the perforated plate 250 may be any suitable length. For example, the length of the perforated plate 250 along the longitudinal direction of the inlet tank 200 may be designed to extend along the inlet tank 200 above a predetermined number of core tubes 220 connected to the bottom portion 205. The width of the perforated plate 250 may be any desirable width, for example, a width the same as that of the inner space 255.

The perforated plate 250 may be a uniformly or non-uniformly perforated plate 250 including a plurality of apertures. A uniformly perforated plate 250 may include a plurality of apertures having a uniform size and shape, and may be uniformly distributed on the plate. A non-uniformly perforated plate may be referred to as “non-uniformly perforated” due to at least one of the following configurations: different sizes among the apertures, different shapes among the apertures, non-uniform distribution (e.g., irregular distribution) of the apertures on the perforated plate 250, etc. The shape of the apertures of a uniformly or non-uniformly perforated plate 250 may be any suitable shape, such as oval, circle, triangle, etc.

FIGS. 5A-5D each show an exemplary non-uniformly perforated plate 250. In the embodiment shown in FIG. 5A, the apertures 251 are in a uniform oval shape but different sizes. The apertures 251 are divided into two groups with two different sizes. For example, as shown in FIG. 5A, a first group of apertures 253 may have a smaller size than a second group of apertures 254. It is contemplated that the first group of apertures 253 may also have a shape (e.g., triangle) that is different from that (i.e. oval) of the second group of apertures 254. The first and second groups of apertures 253 and 254 may be configured to cover a predetermined number of core tubes 220. For example, the first group of apertures 253 may cover a first number of core tubes 220 closer to inlet 210 (e.g., those core tubes immediately below inlet 210). The second group of apertures 254 may be located farther away from the inlet 210 and may cover a second number of core tubes 220 farther away from the inlet 210. The numbers of core tubes 220 located under the first and second groups of apertures 253 and 254 may be properly determined, for example, based on analysis of the fluid dynamics of the air flow 201. It is contemplated that the apertures 251 may include more than two groups of apertures, e.g., three or more groups of apertures. The sizes of the multiple groups of apertures may increase from the group of apertures that are closest to the inlet 210 to the group of apertures that are farthest from the inlet 210. FIGS. 5B to 5D show other exemplary embodiments of the perforated plate 250 with apertures in different shapes. The apertures 251 are in triangular shapes in FIG. 5B, in square shapes in FIG. 5C, and in rectangular shapes in FIG. 5D. It is contemplated that the apertures 251 may have any other suitable shapes.

The inlet tank 200 may include a plurality of pressure balancing openings 270 located at predetermined locations on at least one side (e.g., one side, two sides, etc.) of the inner wall 204. The locations of the pressure balancing openings 270 on the inner wall 204 may be determined, for example, through analysis of the pressure distribution of the air flow 201 in the inlet tank 200. Although the pressure balancing openings 270 are shown in FIG. 3 as a row of rectangular openings distributed on the inner wall 204 and below the perforated plate 250, it is contemplated that pressure balancing openings 270 may adopt various configurations not shown in FIG. 3. For example, the pressure balancing openings 270 may include more than one row on the inner wall 204. The pressure balancing openings 270 may not be lined up in a row, but instead, may be distributed throughout the inner wall 204 at any suitable locations in a pattern or in a random arrangement. Furthermore, the height of the pressure balancing openings 270 may be above or below the perforated plate 250. The pressure balancing openings 270 may be oriented with a suitable angle (e.g., 45 degrees, 90 degrees, 0 degree, etc.) with respect to the perforated plate 250, or with respect to the longitudinal direction of the inlet tank 200. The pressure balancing openings 270 may have any suitable shape, such as square, triangle, rectangle, circle, etc. The term “pressure balancing opening(s)” is intended to encompass any suitable openings on the inner wall 204 that may direct air from one side (where air pressure is higher) of the pressure balancing openings 270 to another side (where air pressure is lower), thereby balancing the pressure of the air flow in the inlet tank 200.

FIG. 6 is a schematic illustration of an exemplary cross-section of an inlet tank 300 that may be employed in the first air-to-air cooling assembly 55 shown in FIG. 2. The inlet tank 300 may include a top portion 303, a bottom portion 305, and a wall 304 forming the left and right ends and the front and back sides of the inlet tank 300. The wall 304 may include a single wall, which together with the top portion 303 and the bottom portion 305, may define a space 355 inside the inlet tank 300. The inlet tank 300 may include an inlet 310, through which an air flow 301 may be directed into the space 355 (in the following descriptions, air flow 301 is also used to refer to the entire air flow in the space 355). A perforated plate 350 may be disposed adjacent the inlet 310 and substantially perpendicular to the air flow 301 directed into the space 355. The perforated plate 350 may have a structure similar to the perforated plate 250 discussed above in connection with FIGS. 3-5, and may be a uniformly or non-uniformly perforated plate. A plurality of pressure balancing openings 370 may be located at predetermined locations on the wall 304, and may be selectively connected via passages 380. For example, the pressure balancing openings 370 may be located on the front and back sides, and the left end of the inlet tank 300. Pressure balancing openings 370 on the front side of the wall 304 may be connected with each other by passages 380, and may be further connected with those openings on the left end of the wall 304. Pressure balancing openings 370 on the back side of the wall 304 may also be connected with each other by passages 380, and may be further connected with those openings on the left end of the wall 304. In some embodiments, the pressure balancing openings 370 on the front side of the wall 304 may be connected with the pressure balancing openings 370 on the back side of the wall 304 through passages 380. An exemplary connection by passages 380 is shown in dotted lines in FIG. 6. Passages 380 may be, for example, metal pipes, or any other suitable passages, and may be disposed external to the inlet tank 300. The manner in which the pressure balancing openings 370 are selectively connected through the passages 380 may be determined, for example, according to the analysis of the pressure distribution of the air flow 301 in the space 355. The pressure balancing openings 370 may be configured to direct the air flow 301 into and out of the space 355 through the passages 380. FIG. 7 is a schematic cross-section view of the inlet tank 300 along the line 7-7 shown in FIG. 6.

FIG. 8A is a schematic illustration of an exemplary cross-section of an inlet tank 400 that may be employed in the first air-to-air cooling assembly 55 shown in FIG. 2. The inlet tank 400 may include a top portion 403, a bottom portion 405, and a wall 404. The wall 404 may include a single wall and may form a space 455 inside the inlet tank 400. The inlet tank 400 may also include an inlet 410, through which an air flow 401 may be directed into the space 455.

The inlet tank 400 may also include a perforated plate 450 disposed within the inlet tank 400 adjacent the inlet 410 and connected with the wall 404. The perforated plate 450 may be disposed substantially perpendicular to the air flow 401. The perforated plate 450 may have a structure similar to the perforated plates 250 and 350 discussed above in connection with FIGS. 3-6, and may be a uniformly or non-uniformly perforated plate. In some embodiments, the perforated plate 450 may be a uniformly perforated plate, which may include a plurality of uniformly distributed apertures of the same shape and size. For example, the perforated plate 450 may include a honey-comb structure with a plurality of honey-comb shaped apertures 451, an exemplary configuration of which is shown in FIG. 9. In some embodiments, the perforated plate 450 may also be a non-uniformly perforated plate similar to the perforated plate 250 illustrated in FIG. 5A. The perforated plate 450 may be located inside the inlet tank 400 adjacent the wall 404 and covering the inlet 410. In some embodiments, the apertures 451 may be connected with an opening portion on the wall 404, as shown in FIG. 8A. In some embodiments, the perforated plate 450 may also be disposed within the opening portion of wall 404 to cover the inlet 410. In some embodiments, the perforated plate 450 may be fixed to the wall 404 through brackets 453, as shown in FIG. 8B, and may be disposed apart from the wall 404 with a predetermined distance. The perforated plate 450 may be substantially perpendicular to the air flow 401. The perforated plate 450 shown in FIG. 8B may be a uniformly or non-uniformly perforated plate discussed above, although a non-uniformly perforated plate is shown.

The inlet tank 400 may include a plurality of pressure balancing openings 470 located at predetermined locations on the wall 404. In a manner similar to the arrangement shown in FIG. 6, the pressure balancing openings 470 may be selectively connected via passages 480. Through the pressure balancing openings 470 and the passages 480, air may be directed from one location to another within the space 455, thereby balancing pressure of the air flow 401 in the inlet tank 400 and achieving better distribution of the air flow 401 and associated thermal load. The passages 480 may be disposed external to the inlet tank 400.

Inlet tank 400 may include one or more curved corner 492. An exemplary curved corner 492 is shown in FIG. 8A at the right-hand bottom corner portion of inlet tank 400, formed between a lower portion of the wall 404 and the bottom portion 405, and adjacent the inlet 410. The curved corner 492 may be a separate structure filling the corner portion, or may be an integral portion extending from the wall 404 or the bottom portion 405. The curved corner 492 may include a curved surface 490 facing the space 455 and inclined with respect to the bottom portion 405, as shown in FIG. 8A. The curved surface 490 alternatively may be a flat inclined surface (not shown) with a slope with respect to the bottom portion 405. The curved corner 492 having the curved surface 490 may help reduce recirculation at the corner of space 455. Although the curved corner 492 is only shown at the corner portion adjacent the inlet 410, it is contemplated that such curved corner 492 having the curved surface 490 may be applied to each corner of the inlet tank 400. The inlet tank 400 may be designed such that a predetermined minimum distance is maintained between the curved corner 492 and the core tube 220 nearest the curved surface 490. It is also contemplated that a curved corner similar to curved corner 492 may be employed in inlet tanks 200 and 300 shown in FIGS. 3 and 6 to help reduce recirculation of air at the corners of inlet tanks 200 and 300.

INDUSTRIAL APPLICABILITY

The disclosed air-to-air cooling assembly may be utilized in any systems or machines where it is desirable to reduce the temperature of a relatively hotter air flow (e.g., a compressed intake air flow for an internal combustion engine) using a relatively cooler air flow. The disclosed air-to-air cooling assembly may enable uniform distribution of the hotter air flow inside the inlet tank and the core tubes of the air-to-air cooling assembly, thereby achieving efficient cooling and reducing or eliminating damage to the core tubes due to thermal gradient caused by non-uniform air flow distribution.

Referring to FIG. 2, the air flow 201 may be directed into the inlet tank 200 of the first air-to-air cooling assembly 55, for example, from the low pressure compressor 46 (shown in FIG. 1). The air flow 201 may flow throughout the inlet tank 200, and may be directed to the core tubes 220 connected to the bottom portion 205 (shown in FIG. 3) of the inlet tank 200. At the core tubes 220, heat exchange may take place between the air flow 201 inside the core tubes 220 and cooling air flowing by the outer surfaces of the core tubes 220. As a result, the temperature of the air flow 201 inside the core tubes 220 may be reduced. The cooled air flow 201 may be directed from the core tubes 220 to the outlet tank 230, and may be further directed into other components, e.g., the air intake manifold 15 (shown in FIG. 1), through the outlet 240 of the outlet tank 230.

Referring to FIGS. 3-5, the perforated plate 250 and pressure balancing openings 270 may improve uniform distribution of the air flow 201 in the inlet tank 200, and subsequently in the core tubes 220. As the air flow 201 enters the inlet tank 200 through the inlet 210, the air flow 201 is intercepted by the perforated plate 250. Perforated plate 250 may prevent the air flow 201 from directly impacting the bottom portion 205 and thereby causing a large portion of the air flow 201 to be directed into a few core tubes 220 closer to the inlet 210. Perforated plate 250 may help divert the air flow 201 toward portions of the inlet tank 200 more distant from inlet 210. As a result, the core tubes 220 farther from the inlet 210 may then receive a balanced portion of air relative to the core tubes 220 closer to the inlet 210. Perforated plate 250 also may prevent air flow 201 from impacting the bottom portion 205 at full velocity and creating turbulence and recirculation.

Perforated plate 250 may regulate the amount of air directed to the core tubes 220 closer to the inlet 210 and farther away from the inlet 210 by selecting one of the size and distribution of the first and second groups of apertures 253 and 254. For example, the first group of apertures 253 may be selectively distributed on the perforated plate 250 such that the first group of apertures 253 cover a first predetermined number of core tubes closer to the inlet 210. The first group of apertures 253 covering the first predetermined number of core tubes 220 may have a relatively smaller size compared to that of the second group of apertures 254. The second group of apertures 254 may be selectively distributed on the perforated plate 250 such that the second group of apertures 254 cover a second predetermined number of core tubes farther away from the inlet 210. The second group of apertures 254 covering the second predetermined number of core tubes 220 may have a relatively larger size compared to that of the first group of apertures 253. In this way, the amount of the air flow 201 directed to the first number of core tubes 220 closer to the inlet 210, and the second number of core tubes 220 farther away from the inlet 210 may be regulated so that a better distribution of the air flow 201 between the core tubes 220 farther away from the inlet 210 and the core tubes 220 closer to the inlet 210 may be achieved.

The pressure balancing openings 270 shown in FIGS. 3 and 4 may enable the air flow 201 to flow back and forth between the inner space 255 and the outer space 206. Specifically, the air flow 201 may be directed from a location in the inlet tank 200 where air pressure is relatively high to another location where air pressure is relatively low. For example, if the air pressure at the inner space 255 side of a particular pressure balancing opening 270 is higher than that at the outer space 206 side of the particular pressure balancing opening 270, air may be directed from the inner space 255 side of the pressure balancing opening 270 to the outer space 206 side of the pressure balancing opening 270 through the pressure balancing opening 270, and vise versa. Due to the fluid communication between different portions of the air flow 201 at different locations via the pressure balancing openings 270, the pressure of the air flow 201 at different locations of the inner space 255 and the outer space 206 may be balanced. As a result, air may be more uniformly distributed in the inlet tank 200. Subsequently, air distribution among the core tubes 220 may become more uniform. Since thermal energy carried by the air flow 201 is directly related to the amount and mass of air flow, thermal energy distribution among the core tubes 220 may become uniform as a result of uniform air flow distribution. Therefore, thermal gradient among the core tubes 220, which may cause thermal stress among the core tubes 220, may be reduced or eliminated.

In the embodiment shown in FIGS. 6 and 7, the air flow 301 may be directed into the space 355 of the inlet tank 300 through the inlet 310, and may be intercepted by the perforated plate 350. Similar to the perforated plate 250 discussed above, the perforated plate 350 may divert the air flow 301, reduce the velocity of the air flow 301, and regulate the amount of the air flow directed to the core tubes 220 through selection of at least one of the size and distribution of the apertures thereon (not shown). Since the pressure balancing openings 370 may be selectively connected by the passages 380, the air flow 301 may be directed from one pressure balancing opening to another through the passages 380. As a result, uneven air pressure distribution in the air flow 301 at different locations of the inlet tank 300 may be balanced. Therefore, air pressure distribution may become uniform. Similar to the discussion of the embodiment shown in FIG. 3, uniform distribution of the air flow 301 in the inlet tank 300 and in the core tubes 220 may be achieved. Connecting the pressure balancing openings 370 through passages 380 and using a single wall for the inlet tank 300 may simplify manufacturing and may reduce cost compared to double wall embodiments.

Referring to FIG. 8A, in some embodiments, the air flow 401 may flow into the inlet tank 400 in a direction parallel with the longitudinal direction of the body of the inlet tank 400. The inlet 410 may be located on or adjacent an end portion of the wall 404 (e.g., the right-hand end of the wall 404). The perforated plate 450, which may be a uniformly or non-uniformly perforated plate, and may regulate the air flow 401 so that the air flow 401 is uniformly spread out when the air flow 401 enters the inlet tank 400 through the inlet 410.

The air flow 401 may be directed from one location to another within the inlet tank 400 through the pressure balancing openings 470 selectively connected by the passages 480. Thus, the pressure of the air flow 401 in the space 455 may be balanced. The curved corner 492 with the curved surface 490 may help reduce recirculation in the air flow 401, thereby improving distribution of the air flow 401 in the inlet tank 400, and subsequently, in the core tubes 220.

By utilizing the perforated plate and the pressure balancing openings, air flow distribution in the inlet tank may become more uniform. As a result, the air distribution in the core tubes connected to the inlet tank may also become uniform. Uniform air distribution among the core tubes may improve cooling efficiency. In addition, uniform air distribution among the core tubes may also reduce damage that can be caused by a thermal gradient due to uneven thermal energy distribution associated with non-uniform air flow distribution. As a result, the durability of the air-to-air cooling assembly may be improved.

It will be apparent to those skilled in the art that various modifications and variations can be made in the disclosed air-to-air cooling assembly. Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the disclosed embodiments herein. It is intended that the specification and examples be considered as exemplary only, with a true scope of the disclosure being indicated by the following claims. 

1. An air-to-air cooling assembly, comprising: an inlet tank including an inlet configured to receive an air flow, and a wall forming a space within the inlet tank; a perforated plate disposed adjacent the inlet of the inlet tank and arranged substantially perpendicular to the air flow; and a plurality of pressure balancing openings at predetermined locations on the wall and configured to direct air into and out of the space.
 2. The air-to-air cooling assembly of claim 1, wherein the perforated plate is a non-uniform perforated plate including a plurality of apertures with at least one of a different size or shape.
 3. The air-to-air cooling assembly of claim 2, wherein the apertures include first and second groups of apertures, the first group of apertures having a size different from that of the second group of apertures, and wherein the first and second groups of apertures cover a predetermined number of core tubes.
 4. The air-to-air cooling assembly of claim 1, wherein the perforated plate is a uniformly perforated plate including a honey-comb structure.
 5. The air-to-air cooling assembly of claim 4, wherein the uniformly perforated plate including a honey-comb structure is disposed within the inlet tank adjacent the inlet.
 6. The air-to-air cooling assembly of claim 1, wherein the perforated plate is fixed to the wall with brackets and disposed apart from the wall by a predetermined distance.
 7. The air-to-air cooling assembly of claim 1, wherein the wall is an inner wall and the space is an inner space, and the inlet tank further includes an outer wall surrounding the inner wall, and wherein the inner wall and the outer wall form an outer space therebetween, the air-to-air cooling assembly further including a plurality of core tubes connected to a bottom portion of the inlet tank to receive air flow from the inner space.
 8. The air-to-air cooling assembly of claim 7, wherein the pressure balancing openings are located on the inner wall and are configured to direct air flow between the inner space and the outer space.
 9. The air-to-air cooling assembly of claim 1, wherein the pressure balancing openings are selectively connected through passages disposed external to the inlet tank, and wherein the pressure balancing openings are configured to direct the air flow into and out of the space through the passages.
 10. The air-to-air cooling assembly of claim 1, wherein the inlet tank further includes at least one curved corner adjacent the inlet within the inlet tank.
 11. A method of distributing air in an air-to-air cooling assembly, comprising: directing an air flow into an inlet tank through an inlet; directing the air flow through a perforated plate disposed adjacent the inlet and substantially perpendicular to the air flow; and directing the air flow into and out of a space formed by a wall of the inlet tank through a plurality of pressure balancing openings on the wall.
 12. The method of claim 11, wherein the wall is an inner wall and the space is an inner space, and wherein the inlet tank further includes an outer space formed by the inner wall and an outer wall enclosing the inner wall, the method further including directing the air flow between the inner space and the outer space through the pressure balancing openings on the inner wall.
 13. The method of claim 11, wherein the pressure balancing openings are selectively connected through passages, the method further including directing the air flow into and out of the space through the pressure balancing openings and the passages.
 14. The method of claim 11, further including regulating the air flow through the perforated plate by selecting one of the size or distribution of apertures within the perforated plate.
 15. The method of claim 11, further including reducing recirculation of the air flow by a curved corner within the inlet tank.
 16. An engine system, comprising: an engine including a plurality of combustion chambers configured to combust a mixture of air and fuel; and an air intake system, including: a compressor configured to compress air supplied to the engine; an air intake manifold configured to distribute air to the engine; and an air-to-air cooling assembly configured to cool the compressed air, the air-to-air cooling assembly including: an inlet tank including a wall forming a space within the inlet tank, and an inlet configured to receive an air flow from the compressor; a perforated plate arranged substantially perpendicular to the air flow and disposed adjacent the inlet of the inlet tank; and a plurality of pressure balancing openings located at predetermined locations on the wall and configured to direct air into and out of the space.
 17. The engine system of claim 16, wherein the perforated plate is a non-uniform perforated plate including a plurality of apertures with at least one of a different size or shape.
 18. The engine system of claim 17, wherein the apertures include a first and a second group of apertures, the first group of apertures having a size different from that of the second group of apertures, and wherein the first and second groups of apertures cover a predetermined number of core tubes.
 19. The engine system of claim 16, wherein the wall is an inner wall and the space is an inner space, and the inlet tank further includes an outer space formed between the inner wall and an outer wall enclosing the inner wall, and wherein the air-to-air cooling assembly further includes a plurality of core tubes connected to a bottom portion of the inlet tank to receive air flow from the inner space.
 20. The engine system of claim 16, wherein the pressure balancing openings are selectively connected through passages. 